Driving mandrel



J. H. THORNLEY DRIVING MANDREL May 5, 1964 2 Sheets-Sheet l Filed Nov. 24. 1961 INVENTOR. JsejnvHT/wrny,

May' 5, 1964 J. H. THoRNLEY 3,131,544

DRIVING MANDREL Filed Nov. 24, 1961 2 Sheets-Sheei 2 United States Patent() 3,is1,544 parvint@ MANDL Joseph H. Thornley, Douglaston, NX. Western Foundation Corporation, 2 Park Ave., New York 16, NY.)

Filed Nov. 24, 1961, Ser. No. 154,512 S Claims. (Cl. 6in-53.72)

l'Ihe present invention relates to driving mandrel for driving thin metal pile shells into the ground in connection with the construction of a foundation.

Various attempts have heretofore been made to develop expansible driving mandrels with indilferent success. The art recognizes the need for a simple, rugged, low upkeep driving mandrel by which thin sheet metal shells having circumferential corrugations may be satisfactorily driven into position for iilling with concrete. The corrugations are desirable to maintain the general cylindrical shape of the thin sheet metal shells during handling.

The utilization of a driving mandrel in 1a corrugated sheet metal shell requires that the leaves of the mandrel have corrugated surfaces matching the corrugations of the shell. The mandrel must be contract-ible to a diameter which `will clear the inner diameter, that is, the minimum diameter of the corrugations, and it must be expansible in an amount great enough to lill the corrugations. This is necessary, otherwise there is danger of injury to the shell by engagement with sharp rocks and the like, Iand even the friction of the soil 'with the corrugated surface might injure the shell.

The contraction of such a mandrel must be performed before any lifting effect is exerted upon the mandrel o-r the shell, otherwise the driven shell may inadvertently be raised and thereby lose its end bearing even when lled with concrete.

A mandrel of this character is subjected to very severe punishment in use, since the driving is eected by .blows of a pile driving hammer. This subjects .all of the parts to either the direct stress of driving or the stress of severe vibration, or both. I have found that it is desirable to avoid all small parts, including pivoted linkages :or like inflexible parts, since they are generally subject to rapid deterioration by the .pounding and vibration incidental to use. According to my invention, I connect the leaves and the head and -foot members by flexible connections, consisting of stranded wire cables which I have found to be lable to withstand vibrational stresses without the rapid deterioration incidental to pivoted linkages and the like. Also the use of such standard wire cable connections simplifies and reduces .the number `of parts involved in the construction of a device of this char-acter.

Pile shells of the type to which my invention may advantageously be applied may be of any desired dimensions. A typical pile shell for this service would be 12 inches nominal diameter of 18 gauge corrugated steel with a welded or otherwise formed water tight seam, the corrugations, particularly Where the same are circumferential,

Vthat is, -at right angles .to the .longitudinal taxis, being, :for

example, substantially one-half inch deep )from the top of the ridge -to the adjacent bottom of the valley, ywith a two inch pitch. rPhe invention may be :applied to the driving of various forms of pile shells, such as stepped shells, that is, shells constructed :of sections of succesively larger diameter toward the top. The shell, Whether of uniform or of stepped diameter may be driven in two :or more stages, particularly to avoid the necessity for guide lea-ds of excessive length. The mandrel may be made in stepped form, or two sections of mandrel of the same or of different diameter may be employed as the occasion may require. The shell may be driven to the desired depth, and 4then extended by the .use of the so called composite pipe extension in accordance with known practice.

3,131,544 Patented May 5, 1964 ICC The chief object of the present invention is to provide a rugged driving mandrel of simple construction and capable of giving extended uninterrupted service.

A further object is to provide a mandrel for .this service which will remain in operation without requiring continuous maintenance, which is expensive to the operator who must suspend activities While the mandrel is being repaired or replaced.

According to the preferred form of the invention, I employ a fluid pressure motor for contracting and exp-anding the leaves of the mandrel by endwise movements of a longitudinal operating rod.- The expanding means preferably consists of two or more wedging means spaced along the length of the leaves and the operating rod, so that they may be moved outwardly by motion of translation parallel .t-o each other tor filling the shell. The contracting means preferably comprises transverse connecting means in .the form of flexible cable links between opposed pairs of leaves. And link operating means connected with the operating rod; the timing of the operation of the contracting means relative to the operation of the expanding means is such that the expanding means is suiiiciently disengaged and out of the way before the contracting means begins to operate that the contracting means may operate Without interference from the expanding means, and that the operation of the two means are so related that when the expanding means is operated, the contracting means does not interfere with its operation. When the mandrel is in the lshell and the leaves are expanded inside the shell yas in the case when a shell is being driven to the desired position, the expanding means is effective to prevent or block radially inwardly or collapsing movement of the leaves. When it is desired to Withdraw the mandrel trom the shell, the operating rod is' irst moved endwise to shift the expanding means to .a position in which it cannot block inward or collapsing movement of the leaves. Upon further endwise movement of the operating rod in the sain-e direction, said rod will cause the flexible link of the contracting means to be shortened by lateral deflection of the link intermediate its ends and cause inward or collapsing movement of Ithe leaves to be produced. This permits the contracting means to move the leaves at a rate different from that of the expanding means.

Upon reverse movement of the rod, the flexible links of the contracting means 'will be released to permit the leaves to be expanded, that is, to be moved radially outward by the expanding means without interference 'from the contr-acting means. -Thus there is seen to be lost moh tion of the rod with respect to the contracting means and the expanding means .to insure that the contracting means is not operated `until the expanding means is actuated to release theleaves `and vice Versa. The expanding means will not be actuated until after the contracting means has been :actuated .to release the leaves. This is brought about by providing a lost motion connection between the rod fand the contracting means on the Ione hand, and bet-Ween closure of a specific embodiment. 6()Y Now in order to acquaint those skilled in the art with the manner of constructing and operating my invention, I shall describe, in connection fwith the accompanying drawings, -a specific embodiment which is here employed to explain the invention and not to limit the same.

In the accompanying drawings,in which like reference numerals indicate like parts:

FIGURE 1 is a vertical, longitudinal sect-ion through la driving mandrel of my invention, shown as inserted in a transversely corrugated sheet met-al shell;

FIGURE 2 is a similar View of the mandrel expanded into contact with the Walls yof the shell;

FIGURE 3 is a transverse `cross sectional view taken on :the -line 3, 3 of FIGURE 2;

FIGURE 4 is la transverse cross sectional view taken on the line 4, 4 of FGURE 1;

FIGURE Slis a similar view taken on the line 5, 5 of FiGURE 2, showing the transverse cables in the position where they limit the expansion of the mandrel leaves;

FIGURE 6 is a cross section taken on the line 6, 6 of FIG. 2;

FIGURE 7 is a cross section taken on the line 7, 7 of FIG. 2; and

FIGURE 8 is a cross Vsectiontaken on the line S, 8 of FlGURE 2.

The above sections are taken looking in the direction indicated by the arrows.

As shown in the drawings, a thin corrugated metal shell 1 has a closure or end plate 2 at its lower end secured thereto preferably by welding or other adequate joint which is fluid tight and mechanically strong. The colsure plate may have an extending margin or a flange extending out radially beyond the corrugations of the shell for the purpose of pushing aside rock fragments and the like. This shell may be of any desired size or dimension, but may, for example, be approximately l2 inches in diameter with wall thickness of 18 gauge (Birmingham standard 0.0495 inch), and with circular corrugations which are of approximately two inch pitch with the depth of the valley one-half inch. These figures are but by way of example, and may obviously be varied as desired, as may the character of the corrugations employed. Instead of being disposed in planes at right angles to the longitudinal axis, the corrugations may be helical or otherwise according to a predetermined pattern.

The mandrel as a Whole designated at 3 comprises a head plate 4, a foot plate 5, and longitudinally extending leaves 6, 6. Four leaves are shown in the drawings as constituting the preferred embodiment. It is not intended to preclude a greater or less number.

A iluid pressure operated motor or jack 7 is mounted on 0r attached to the head plate 4. The cylinder 8 is provided with an annular frame or flange 7a encircling the upper end thereof. This frame or flange '7a is seated in a recess in the topy of the head plate 4 and the cylinder 8 extends down through a central opening in said head plate 4. The said motor 7 comprises a double ended cylinder 8, with a movable double acting piston 9. The piston 9 is connected with a piston rod or plunger 10 either directly or through a flexible joint. The rod or ,plunger 10 is an operating rod for the expanding and contracting means to be described later. The said rod 1t) is adapted to be moved upwardly by fluid pressure admitted to the bottom side of the piston 9 and downwardly by uid pressure admitted to the top of the piston 9. A longitudinally extending duct 12 in the wall of the cylinder 8 leads from the upper end of the cylinder through a flexible tube 19 to a rotary control valve 13 of known form. Similarly, a duct 14 leads from the bottom of the cylinder 8 through llexible tube 2i) to said control valve 13. This valve 13 as shown has three positions: forward, reverse and lock. The flexible tubular connectors 19 and 20 may be hoses which may be bound together with steam hose for operating the steam hammer, the base plate for which is shown at 32 in FIG- URE 2.

Fluid pressure supply connection 15 to the valve 13 and exhaust connection 16 is adapted to admit and exhaust hydraulic or pneumatic pressure, as desired to operate the duid pressure operated jack 7 in the desired direction. Hydraulic duid is preferred. The rotatable valve body 17 is connected to a control handle 18 by which the body may be shifted in angular position to permit the ports' 19 and 2) to connect as shown in FIGURE 1 to the supply and exhaust connections, respectively. By shifting the handle 1S to the vertical position, the connections 15, 16, 19 and 2t) will all be closed olf, so

that the piston 9 will be locked in position by closed bodies of non-compressible fluid, such as water, oil, grease or the like. Where compressible lluid, such as compressed air, is employed, movement of the handle 18 from the position shown in FEGURE l to the vertical position will result in trapping compressed air above the piston 9. The operating valve 13 may be electrically or otherwise remote controlled.

With the control handle 18 and valve 13 in the position shown in FlGURE 1, hydraulic uid under pressure will be applied to the top of the piston 9, and the hydraulic fluid beneath the piston 9 will be open to exhaust. The piston 9 may thereupon be forced downwardly to a predetermined limited position to expand the leaves of theV mandrel, and the piston 9 may then be locked in position by the movement of the valve to the cutoff position, trapping incompressible liquid on each side of the piston. Shifting the valve 13 by moving the handle 1S to the dotted line position 18a reverses the application of hydraulic fluid under pressure to raise the piston 9 as desired.

The plunger or operating rod 10 extends down longitudinally, substantially coaxially of the body of the mandrel, and has its lower end entered into and guided by a sleeve 22a mounted in the foot plate 5. The extent of downward travel of the plunger or rod 10 may be limited by the engagement of lugs 72 mounted on said plunger 10 against the upper end of the said guiding sleeve 22a. Alternatively, engagement of the piston 9 with the bottom of the cylinder may limit such movement. Alternatively, the transverse stranded wire cable tension members 28, 2S may limit the radially outward travel of the leaves 6, 6. Preferably, the limit of travel of the rod 14) is imposed by the lug 72 striking the guiding sleeve 22a.

The plunger 10 carries two wedge blocks 26, 26 which are spaced from each other along the length of the said rod, and preferably with such spacing between them longitudinally of the leaves as will give adequate support to the leaves in pressing them outwardly against the insides of the shell. For this purpose, a minimum of two such sets of blocks 27 are provided, as shown in FIGURES 1 and 2. Each block 27 is fastened to the inside of the corresponding leaf 6 and presents a tiat sloping face facing inwardly for engagement with one of the flat sloping sides of v`the corresponding wedge member 26 mounted on the plunger 10. Thus, by moving the plunger 10 downwardly relative to the leaves, the wedge blocks 26 are moved with the said plunger against the cooperating faces of the stationary wedge members 27 on the leaves 6, 6 to cause the leaves to travel by motion of translation outwardly from the axis of the mandrel.

The means for contracting the mandrel, that is, for moving the leaves by motion of translation towards the common central longitudinal axis includes the pairs of short transverse stranded flexible Wire cables 28, 28 which constitute flexible links disposed in pairs on opposite sides of the operating rod 10. See particularly FIGURE 5. These short lengths of cable comprise preferably fixed heads on one end and adjustable threaded heads on the other for adjusting the length of said cables 28, 28 to the desired value. The plunger rod 10 carries radially extending link operating means in the form of lugs 72, 72 and moves them in a path which is intersected by the said short flexible links in the form of cables 28, 28, so that the central part of the said cables 28, 28 will be moved transversely of their length, that is, in the direction of movement of the rod 10 which is upwardly inthe speciiic embodiment shown in the drawings. This will in effect shorten said pairs of flexible links or cables 28, and pull the leaves towards each other with a parallel motion of translation.

The relation of the expanding means 26, 27 with respect to the movement of the rod 10 is such as to produce the following effects. At the time that the leaves are contracted by engagement of the lugs 72 with the transverse cables 28, 28, as shown in FIGURE`1, the wedging surfaces of the movable and stationary wedge members 26, 27 are suiciently disengaged and separated as not to block the inward contracting movement of the said leaves 6, 6. This relation is illustrated in FIGURE 1. When the leaves have been contracted to the maximum amount, they may be stopped either by the engagement of the wedging means 26, 27 at top and bottom, or alternatively, the leaves may be stopped by engaging the outside of the cylinder 7 at the top and corresponding stop means in the form of shoulders or ilanges on the foot plate 5, as shown in FIGURE 6.

Upon moving the operating rod lil downwardly to expand the leaves 6, 6, the link operating lugs 72, 72 immediately lose contact with the transverse short cables 23, 28 as the operating surfaces of the wedge members 26, 27 come into expanding engagement. In other words, the slack created in the flexible links or cables 28, 28 by downward movement of the operating rod 10, accumulates faster than the spreading action occurs under the lrelative movement of the movable wedge members 26 in engagement with Ithe wedge members 27. Thereby, interference between the expanding means and the contracting means is obvi-ated. In the contracting motion, the wedges do not block contraction lat least until the leaves have been moved toward each other a maximum distance, and likewise upon expansion of the leaves, the cables 218, 2S which are comprised in the contracting means do not 'block `further spreading movement until the maximum spreading movement has been reached where the cables 28, 28 are fully extended in horizontal position, as shown in FIGURE 2.

Since the downward motion of the plunger rod l is employed to thrust the wedge members 26 between the stationary wedge members 127, 27, the said stationary wedge members 27, 27 Iand the leaves on which they are mounted must be held stationary longitudinally to withstand the thrust of said wedge means 26. Also, the leaves must be retained endwise in position between the head plate 4 and the foot plate 5 to deliver the thrust of the impact blows upon the head plate -4 by the driving mechanism such as a steam hammer. Furthermore, the said leaves must be maintained substantially in parallel relation to each other throughout their various positions, and particularly must be disposed in vertical position between the driving `head plate 4 and the driven `foot plate 5 when the parts are in the position shown in FIGURE 2 ready for driving. Stranded ilexible wire cables 38, 38 are fastened at their upper ends in the head 4 radially outside the cylinder 7 and extend down to the foot plate 5. The said cables at their intermedia-te parts are disposed in recesses formed at the gaps between the edges of adjacent leaves 6, 6, as shown in FIGURE 4. The upper ends of the cables 33 preferably have lixed heads at their upper ends and threaded adjustable nuts 75 :at :their lower ends.

The driving head 4 preferably comprises a cylinder mounting 7a 4in the form of an annular ring of heavy cross section set in a recess in the head 4, as shown in FIGURE 2. The longitudinally extending cables 38 have their fixed heads mounted i-n the driving head '4 below the cylinder mounting body 7a. These cables extend dow-n through guide lugs 77 shown in FIGURES 2 and `8, the guide lugs being welded to the bottom of the head plate member 4 and being disposed in notches `formed at the sides of the upper ends of the leaves 6, as will appear from FIGURE 8, the function of which lugs or Vanes 77 is to guide the said leaves 6, 6 particularly when they are moved to the contracted position to insure a definite location of the upper ends of said leaves.

In similar fashion, the lower ends of the leaves 6, 6 are held in alignment by lugs or vanes 40a, shown more clearly in FIGURE 6. Thus when the mandrel is contracted las shown in FIGURE l, the pulling ltogether of Vthe ends of the transverse short cables r28, 28 insures the seating of the lower ends of the leaves :against the vanes 6 'or lugs 40a, 40a, Iand similarly, the upper ends of the leaves 6, 6 are likewise definitely positioned by engagement Iwith the lugs or vanes`77, 77.

'Ille ends of the leaves 6, 6 may be finished square, that is, in planes at right angles to the longitudinal Alternatively, they may be cone shaped on a flat taper to insure closer contact between the ends of the leaves and said plates at each end when the leaves lare moved outwardly.

As shown in FIGURES 1, 2 and 7, I-I have provided a collar with guiding vanes 73, 73 upon the operating rod 10 at the central portion of the mandrel. These guiding means 73, 73 enter into slots 76 in the leaves 6, 6. These slots are located midway between the lateral edges of the leaves and the vanes and slots cooperate to maintain the leaves in vertical alignment with the rod 10 at all times. It is highly desirable that upon contraction of the mandrel for insertion into the shell 1, the leaves may be gathered compaotly together and in `definite longitudinal and radial alignment, so that the mandrel will be contracted accurately toa predetermined size. Likewise for removal of the mandrel from the driven shell '1, it is necessary to contract the mandrel to the predetermined dimensions without fail, so that the same may be raised without causzing any substantial lifting force to be exerted upon the shell 1. Any disturbance of the shell with respect to the seating to which it has been driven will tend to diminish tor destroy the value of the pile thus installed.

In the employment of shells of thin g-auge, I may arrange 'for the interfitting of the shell with the corrugations on the surface of the leaves by arranging for the corrugations of the shell to be of .a pitch slightly less than that of the mandrel yand then stretching the shell endwise upon the mandrel. The mandrel is then expanded to till the corrugations.

The expansion of the mandrel may be arranged to occur on the upward motion of the operating rod, and the contraction on the downward motion of the rod.

This application is 'a continuation-impart of my copending application Serial No. 729,132, tiled April 17, lS and now abandoned.

I do not intend to be limited to the speciiic details shown and described, :as the scope of the invention is to be determined from the following claims.

I claim:

1. In la driving mandrel for pile shells the combination of a head plate `adapted to be impacted, a foot plate, a plurality of longitudinally extending leaves disposed between said plates -and adapted to transmit driving impact from the head plate to the foot plate, a plurality olf stranded wire cables extending between the head plate [and the foot plate to limit the separation of said plates, a lluid pressure motor having la cylinder mounted on said head plate and having a piston provided with an operating rod extending lengthwise of the mandrel substantially centrally thereof, said piston bein-g adapted tol move the operating rod by applied uid pressure inwardly and outwardly relative to said cylinder, cooperating wedge means connected to said operating rod and to said leaves for moving said leaves apart with substantially parallel mortion to expand them into contact with lthe inside wall of ia pile shell, transversely extending iiexible links connected between said leaves, said links limiting separation of said leaves land being operable by lateral deilection intermediate their ends to pull the leaves toward each other `for collapsing fthe mandrel, said operating rod having link operating means comprising lugs for engaging said links Ito cause them to shorten and to collapse the leaves when the opera-ting rod is moved endwise in one direction, said operating rod being movable endwise in said direction a `distance suicien-t to separate the wedge means to permit collapse of the leaves 'before the link operating means actuates the links to pull the leaves towards each other.

2. The combination of cla-im 1 characterized by said connecting means comprising short lengths of stranded '7 wire cable having their .outer ends anchored in said leaves.

3. The combination of claim 2 further characterized by said link operating means comprising lugs carried on said ope-rating rod, said lugs lying in transverse alignment with .the central portions of said cables lto engage the same between their anchored ends to produce contraction of 4the leaves relative to each other when the operating rod is moved endwise in one directionM 4. The combination of claim 3 wherein said cables are disposed in pairs between opposed leaves and said operating rod has operating projections, the cables of each pair lying transversely in the path of movement et said projections to be engaged thereby after the -wedging means has been previously disengaged by longitudinal movement of the operating rod.

5. The combination of claim 1 characterized by said leaves being four in number and having gaps between them and wherein said longitudinally extending cables .are disposed substantially in yregister with the gaps between :adjacent leaves.

6. In a collapsible and expansible mandrel for driving a pile shell the combination lof a head plate, a foot plate, a plurality of laterally movable leaves disposed endwise between said plates, transverse Wire :cables connected at their ends to said plates to limit their separation from each 'other and for pulling the leaves radially together, a iluid pressure motor carrie-d on said head plate and having a piston rod movable inwardly and outwardly, wedge means operated by outward motion of said pis-ton rod to expand said leaves, means on said rod operating upon continued motion of said rod after said Wedge means lhas been moved to a non-blocking position to en- .gage said cables laterally for contracting said leaves.

'7. In combination in a driving mandrel, a head plate,

a lfoot plate, a series of longitudinally extending leaves adapted -to be moved laterally relative to each other for contracting and expanding said mandrel, said leaves extending between and engaging endwise said head plate and foot plate, a :series of longitudinally extending stranded wire cables connected at their ends to said head plate and said foot plate respectively, a power actuated operating rod, wedge means on said rod and cooperating wedge means on said leaves adjacent each end or" said leaves for producing expansion of the mandrel upon motion of translation of said leaves, contracting means comprising radially projecting llugs on said rod and cooperating contraoting means comprising tnansverse flexible cable links carried ion said leaves adjacent each end of said leaves for producing contraction `of the mandrel through motion of translation of said leaves, said longitudinally extending cables, said expansion means and said contnaction means holding said plates and leaves in alignment in contracted position. t

8. The combination of claim 7 wherein said head plate and foot plate have radially extending lugs disposed between the adjacent edges of said leaves for retaining said plates 4and said leaves in angular and longitudinal alignment.

References Cited in the iile of this patent K UNITED STATES PATENTS 1,872,688 Dealy Aug. 26, 1932 11,978,332 Stern Oet. 23, 1934 2,880,590 Smith Apr. 7, 1959 FOREIGN PATENTS 1,068,306 France Feb. 3, 1954 834,879 Great Britain May 11, 1960 

1. IN A DRIVING MANDREL FOR PILE SHELLS THE COMBINATION OF A HEAD PLATE ADAPTED TO BE IMPACTED, A FOOT PLATE, A PLURALITY OF LONGITUDINALLY EXTENDING LEAVES DISPOSED BETWEEN SAID PLATES AND ADAPTED TO TRANSMIT DRIVING IMPACT FROM THE HEAD PLATE TO THE FOOT PLATE, A PLURALITY OF STRANDED WIRE CABLES EXTENDING BETWEEN THE HEAD PLATE AND THE FOOT PLATE TO LIMIT THE SEPARATION OF SAID PLATES, A FLUID PRESSURE MOTOR HAVING A CYLINDER MOUNTED ON SAID HEAD PLATE AND HAVING A PISTON PROVIDED WITH AN OPERATING ROD EXTENDING LENGTHWISE OF THE MANDREL SUBSTANTIALLY CENTRALLY THEREOF, SAID PISTON BEING ADAPTED TO MOVE THE OPERATING ROD BY APPLIED FLUID PRESSURE INWARDLY AND OUTWARDLY RELATIVE TO SAID CYLINDER, COOPERATING WEDGE MEANS CONNECTED TO SAID OPERATING ROD AND TO SAID LEAVES FOR MOVING SAID LEAVES APART WITH SUBSTANTIALLY PARALLEL MOTION TO EXPAND THEM INTO CONTACT WITH THE INSIDE WALL OF A PILE SHELL, TRANSVERSELY EXTENDING FLEXIBLE LINKS CONNECTED BETWEEN SAID LEAVES, SAID LINKS LIMITING SEPARATION OF SAID LEAVES AND BEING OPERABLE BY LATERAL DEFLECTION INTERMEDIATE THEIR ENDS TO PULL THE LEAVES TOWARD EACH OTHER FOR COLLAPSING THE MANDREL, SAID OPERATING ROD HAVING LINK OPERATING MEANS COMPRISING LUGS FOR ENGAGING SAID LINKS TO CAUSE THEM TO SHORTEN AND TO COLLAPSE THE LEAVES WHEN THE OPERATING ROD IS MOVED ENDWISE IN ONE DIRECTION, SAID 